Fouling of HVAC fin and tube heat exchangers

Conference · Sun Jul 01 04:00:00 EDT 2001

OSTI ID:785280

Siegel, Jeffrey ^[1]; Carey, Van P

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1. LBNL Library

Fin and tube heat exchangers are used widely in residential, commercial and industrial HVAC applications. Invariably, indoor and outdoor air contaminants foul these heat exchangers. This fouling can cause decreased capacity and efficiency of the HVAC equipment as well as indoor air quality problems related to microbiological growth. This paper describes laboratory studies to investigate the mechanisms that cause fouling. The laboratory experiments involve subjecting a 4.7 fins/cm (12 fins/inch) fin and tube heat exchanger to an air stream that contains monodisperse particles. Air velocities ranging from 1.5-5.2 m/s (295 ft/min-1024 ft/min) and particle sizes from 1--8.6 {micro}m are used. The measured fraction of particles that deposit as well as information about the location of the deposited material indicate that particles greater than about 1 {micro}m contribute to fouling. These experimental results are used to validate a scaling analysis that describes the relative importance of several deposition mechanisms including impaction, Brownian diffusion, turbophoresis, thermophoresis, diffusiophoresis, and gravitational settling. The analysis is extended to apply to different fin spacings and particle sizes typical of those found in indoor air.

• Research Organization: Lawrence Berkeley National Lab., CA (US)
• Sponsoring Organization: This study was sponsored/funded by the California Institute for Energy Efficiency(CIEE)through the U.S. Department of Energy. (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 785280
• Report Number(s): LBNL--47668
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR
AIR QUALITY
CAPACITY
DEPOSITION
DIFFUSION
EFFICIENCY
FOULING
HEAT EXCHANGERS
PARTICLE SIZE
THERMOPHORESIS